Protecting wood from attack by insects and fungi



Patented Apr. 11, 193

UNITED STATES PROTECTING WOOD FROM ATTACK BY INSECTS AND 'FUNGI Frank H. Lyons, Milwaukee, Wis., assignor to E. L. Bruce Company, poration of Delaware N 0 Drawing. Application Memphis, Tenn, a cor- 4 December 8, 1930,

Serial No. 500,982

10 Claims.

My. invention relates to the impregnating of wood and the like and has particularly in view the treatment of wood so that it will resist insects and fungi attack, such as from termites and other wood destroying insects and rot fungi.

One of the objects is to provide a toxic treatment that is suitable for window frames, sills, doors and similar structural woodwork. Such a treatment should leave the wood practically colorless, odorless and toxic. It should notv warp the wood and should permit of the wood being readily painted or varnished over.

Water should not be used as a carrying medium for a toxicant on account of its liability to warp the wood. Fuel oils should not be usedbecause of their staining properties and because the treated wood cannot be readily painted or varnished over.

Varnish makers and painters (V. M. and P.) naphtha is a suitable carrying agent, but none of the readily available toxicants are .soluble in it to a degree suflicient to obtain adequate protection from the toxic standpoint.

Another object of the invention is to provide, a suitable method of carrying a toxlcant into the wood with a'carrying medium, in the main portion of which, the toxicant is normally insoluble.

In my prior application, S. N. 422,223, filed January 20, 1930, now Patent No. 2,081,828, is sued May 25, 1937, I have disclosed the use of B-naphthol, as a toxicant, dissolved in fuel oil for the treatment of lumber. B-naphthol, however, is not sufliciently soluble in V. M. and P. naphtha. It is, however, very soluble in ethyl alcohol, whether denatured or not.

I have discovered that if, to a solution of B-naphthol in alcohol, a certain amount of rosin is added, then on mixing. with V. M. and P. naphtha the solution will remain clean,

The proportions of ingredients found to be suitable is as follows:

f I Pounds Alcohol 44.9 Rosin 331 B-naphthol 331 V. M. & P. naphtha 5,050

To mix the ingredients the alcohol is put into the mixer and pale powdered rosin added. After agitating for 15 minutes, the B-naphthol is added and stirred for minutes. The V. M. and P. naphtha is then added slowly, with constant stirring. After complete solution of the rosin in the naphtha, the mixer is ready'to be discharged.

Heretofore, it has not been possible to carry I tical proportions.

95% ethyl alcohol into solution with V. M. and P. naphtha. The presence of the toxicant in the alcohol does not affect to the solubility of thealcohol in the V. M. and P. naphtha.

This formula, due to its low specific gravity, and the fact that alcohol is present, which acts as a wetting agent for the wood fibre, shows rather unusual speed in penetrating the wood. It is found to be particularly effective where it is sprayed on to the wood in such places as the wooden frames of automobile bodies. In structures of this character, protection for.the wood is desired normally for only a period of from four to five years, so that spraying is satisfactory. The same is true when the wood is merely dipped into the solution.

The more toxicant that can be dissolved in thesolvent, within certain limits, the higher the factor of safety of the treated wood. This is especially true where the treating composition is sprayed on the wood or applied by dipping, with the resulting low penetration. In the for.- mula given, using about 5% B-naphthol by weight of the composition, there will ,be no serious crystallization if the composition is stored" outdoors during cold weather. However, if the amount of B-naphthol is increased by as much as 50%, it will go into solution at room temperature, although this is about thelimit of solubility; but at low temperatures, someof the B- naphthol will crystallize out.

As alcohol is much more expensive than thenaphtha, it is desirable to use as littlealcohol as possible. The proportion of alcohol given in the example is about the least practical amount that can be used. Using this proportion of alcohol, the toxicant will remain in solution at room temperature but some will havea tendency to crystallize out at low temperatures.

The maximum amount of rosin that can be bility in the solvents. V i

The naphtha'will be used in thegreatest prac- It will be understood that the I any substantial extent used is determined only by the limits of its solu- 1 "naphtha is the diluent or carrying agent and its proportion in the its cost and the, conditions to which the treated wood will be subjected. By using the proportions given in the example, a balanced system is provided which contains approximately 5% by weight of B-naphthol,. which is a convenient strength to work with as it gives a high facton of safety for the impregnated wood.

formulawill depend upon how concentrated the treating composition should be, I

tions Instead of using ethyl alcohol, with rosin, I may use propyl alcohols, or butyl alcohols, or amyl alcohols with or without rosin, for getting the B-naphthol into solution in the naphtha. I can also use an acetate, such as ethyl acetate or a ketone, such as acetone, with rosin.

Instead of using rosin in the composition, I may use calcium resinate, which is a limed rosin; or ester gum.

Instead of the naphtha, I may use benzol, toluol, xylol, turpentine and carbon tetrachloride.

There are many other organic toxics that are soluble in alcohol and that can be-dissolved in a rosin and V. M. and P. naphtha medium. The following are found to be adaptable for this purpose.

p-Dichlorobenzene, 1-3-5-trichlorobenzene, mdihydroxy-benzene (resorcinol), o-dihydroxybenzene (catechol), l-2-3'-'trihydroxybenzene (pyrogallol), mono-benzene-sulphonic acid, diphenyl, alpha-naphthol, alpha-naphthylamine, beta-chloro-naphthalene and alpha-nitro-naphthalene.

In conjunction with B-naphthol, dinitrophenolaniline may be used in the proportion of 5% B- .naphthol and 1% of dinitrophenol-aniline and which gives an extremely high toxicity. Water is only very slightly soluble in the aforesaid formulae.

When using the above compositions the treated materials are practically the same color as the untreated materials. For treating certain types of wood construction, such as the wood framework of automobiles, it is desirable that it should have the appearance of being painted A black coating can besecured by adding 10% of asphalt to the treating composition.

A suitable composition may be prepared in the following manner:

7.00 lbs. of asphalt of'the following specifica- Melting point, 190-200" F.,

found to be particularly suited for the purpose.

Penetration at 77 F. 10-16, Specific gravity at 60 F. not less than 1, Solubility at C. 8.2 not less than 99.5, Flash ASTM not less than 460 F.,

-thol is in solution 700 gallons of V. M. 8: P. naphtha is added and the mixture stirred until complete solution of the rosin takes place. The asphalt paint is then added to the mixture.

This product can be used as an asphalt paint with very high toxic properties. The asphalt will be beneficial in preventing extreme leaching of the toxicant and gives the desired appearance.

It is not necessary to use asphalt of this particular specification, although this asphalt is Other colors may be added to the solution in the form of soluble 'dyes or in the case of spraying, certain pigments may be added.

V. M. and P. naphtha is defined as a petroleum distillate with initial boiling point not less than F. and an end point of 550 F. I prefer one Pounds Rosin 331 Alcohol 449 B-naphthol 331 V. M. 8; P. naphtha 5,050

2. A composition containing a normally solid organic toxicant represented by B-naphthol, a solvent for the toxicant from the group consisting of ethyl alcohol and rosin, propyl, butyl and amyl alcohol and a volatile solvent therefor in which the toxicant by itself is substantially insoluble and selected from the group consisting of naphtha, benzol, toluol, xylol, turpentine and carbon tetrachloride, the ingredients being miscible and in such proportions as to form a clear solution. v

3. Structural woodwork containing a,mixture of rosin and crystalline B-naphthol in an amount to produce a high degree of toxicity against insect and fungi attack.

4. Structural woodwork containing B-naphthol in an amount to produce a high degree of toxicity against insect and fungi attack, substantially all of the IB-naphthol being in crystalline form.

5. The method of protecting wood from attack by insects and fungi which comprises treating the wood with a readily volatile solvent containing about 5% of B-naphthol, which crystallizes on the wood after evaporation of the solvent.

6. The method of protecting wood from attack behind in the pores of the wood in a crystalline form after volatilization of the solvent and in an amount to produce a high degree of toxicity, the toxicant being selected from the group. consisting of p-dichlorobenzene, 1-3-5-trichlorobenzene, mdihydroxybenzene (resorcinol), benzene (catechol), 1-2-3-trihydroxybenzene (pyrogallol), mono-benzene-sulphonic acid, diphenyl, alpha-naphthol, beta-naphthol, alphanaphthylamine, beta-chloro-naphthalene and valpha--nitro-naphthalene.

7. Themethod of preserving materials normally subject to attack by fungi which comprises impregnating the materials with a-nitro-naphthalene.

8. The method of preserving materials normally subject to attack by fungi which comprises treating the materials with a solution of a-nitronaphthalene.

'9. The method of protecting wood from fungi and the like which comprises impregnating the wood with a-nitro-naphthalene.

10. The method of protecting wood "from fungi and the like which comprises treating the wood with a solution of a-nltro-naphthalene.

that has an initial boiling point from zoo-300 F.

and an end point around 412. F.

Inasmuch as the alcohol and the V. M. I: P.

o-dihydroxy- 3 

